Thermally efficient connector system

ABSTRACT

A connector assembly can be provided. A receptacle includes terminals that can be positioned in a card slot on a 0.60 mm pitch (or greater). A biasing element can be provided in the card slot to engage a mating paddle card. The receptacle can be configured to allow air to flow from a front face to a rear face, the air passing through a middle wall. A plug assembly can be provided that includes a conductive body and is configured to generate some amount of heat. The body can include a surface that has cooling grooves. The cooling grooves allow air flow over the plug assembly so that the plug assembly can be cooled directly.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 15/109,862, filed Jul. 6, 2016, now U.S. Pat. No. 9,960,553, which is a national phase of PCT application Ser. No. PCT/US2015/022,705, filed Mar. 26, 2015, which claims priority to U.S. Provisional Application No. 61/971,366, filed Mar. 27, 2014, all of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

This disclosure relates to field of connectors, more specifically to connectors suitable for supporting increasing needs for density.

DESCRIPTION OF RELATED ART

Input/Output (IO) connectors are well known. Some of the common types include SFP, QSFP and CXP style connectors. One way these connectors tend to be used is a rack mounted switch so that a number of connections can be provided to other devices and high band width requirements can be supported. These connectors, while useful, tend to be configured to provide terminals in a card slot at a 0.8 or 0.75 pitch. Each card slot can have terminals on two sides of the card slot. Thus, the pitch the terminals are positioned on tends to limit the number of terminals that be provided in row and thus limits the bandwidth that can be supported by a 1U rack system. While IO connectors with small pitches are known, conventional IO connectors that use a paddle card in a plug connector (e.g., SFP, QSFP, CXP) are at 0.75 mm or larger pitch so as to accommodate the tolerances inherent in the paddle card that is inserted into the card slot (as the paddle card is typically formed with a PCB construction). Removing the paddle card could potentially help improve tolerance stack-up but the paddle card is desirable as it can support circuitry that allows the system to work, particularly for active copper and optical based plug assemblies.

It has been determined that when attempting to provide a card slot with terminal at 0.65 mm or less the tolerances of the circuit board that are used to form a paddle card become problematic if conventional construction techniques are used. One approach to help resolve this issue has been to use a biasing element in a cage that help bias the plug connector toward one side of a port. However, certain individuals would appreciate further improvements to a connector system.

In addition, existing systems tend to be difficult to cool, especially if the systems are arranged in a stacked configuration. Thus, certain individuals would appreciate a connector system that could help address thermal management issues.

SUMMARY

A connector is provided that has terminals in a card slot arranged in a pitch of 0.6 mm-0.65 mm (e.g., between 0.59 and 0.66). A biasing member is provided on one end of the card slot to provide sufficient tolerance control. The connector can be configured so as to support active cable assemblies and optical modules (e.g., modules that create a thermal load) and in an embodiment can support modules that generate 2 watts of power. To provide cooling in a stacked configuration, air flow is directed through the connector, over the module and out the back of the connector so that the module can be cooled directly with air flowing through the system.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which:

FIG. 1 illustrates a perspective view of an embodiment of a receptacle assembly mated to a plug assembly.

FIG. 2 illustrates a perspective view of the embodiment depicted in FIG. 1 with one of the plug assemblies in an unmated state.

FIG. 3 illustrates another perspective view of the embodiment depicted in FIG. 1 with one of the plug assemblies omitted.

FIG. 4 illustrates a partially exploded perspective view of the embodiment depicted in FIG. 3.

FIG. 5 illustrates an elevated front view of the embodiment depicted in FIG. 3.

FIG. 6 illustrates an elevated side view of the sectional taken along line 6-6 in FIG. 2.

FIG. 7 illustrates a perspective view of the embodiment depicted in FIG. 6.

FIG. 8 illustrates a simplified perspective view of the embodiment depicted in FIG. 7.

FIG. 9 illustrates a partially exploded perspective view of the embodiment depicted in FIG. 9.

FIG. 10 illustrates another perspective view of the embodiment depicted in FIG. 9.

FIG. 11 illustrates another perspective view of the embodiment depicted in FIG. 8.

FIG. 12 illustrates an enlarged perspective view of the embodiment depicted in FIG. 2.

FIG. 13 illustrates a perspective view of the sectional taken along line 13-13 in FIG. 2.

FIG. 14 illustrates a perspective view of the sectional taken along line 14-14 in FIG. 2.

FIG. 15 illustrates a perspective view of the sectional taken along line 14-14 in FIG. 2.

FIG. 16A illustrates a perspective view of another embodiment of a receptacle assembly.

FIG. 16B illustrates an enlarged perspective view of the embodiment depicted in FIG. 16A.

FIG. 17A illustrates a perspective view of the sectional taken along line 17-17 in FIG. 16A.

FIG. 17B illustrates an elevated front view of the embodiment depicted in FIG. 17A.

FIG. 18 illustrates a perspective view of the sectional taken along line 18-18 in FIG. 2.

FIG. 19 illustrates a simplified elevated front view of the embodiment depicted in FIG. 18.

FIG. 20 illustrates a partial perspective view of an embodiment of a receptacle assembly.

FIG. 21 illustrates another perspective view of the embodiment depicted in FIG. 20.

FIG. 22 illustrates another perspective view of the embodiment depicted in FIG. 20.

DETAILED DESCRIPTION

The detailed description that follows describes exemplary embodiments and is not intended to be limited to the expressly disclosed combination(s). Therefore, unless otherwise noted, features disclosed herein may be combined together to form additional combinations that were not otherwise shown for purposes of brevity. In addition, the depicted features may be used alone or in combination with a subset of the other depicted features so as to provide functionality that is appropriate for the corresponding application. Thus, the depicted embodiments are not intended to be limiting unless otherwise noted.

Turning to the Figs., a connector assembly 10 is mounted on a circuit board 5. The connector assembly includes a cage 30 and has ports 12 that are configured to receive plug assemblies 90.

As is known, a plug assembly can include a cable 93 attached to a body 92 and the depicted embodiment includes a latch 91 that is configured to allow a latch system to releasably engage the receptacle assembly 10. Alternative embodiments of a plug assembly could include a body that does not have a cable attached to it (such as embodiments that provide for optical connectors that can plug into the plug assembly). The body 92 protects a paddle card 95 that can have pads on a 0.65 or 0.60 pitch and the paddle card 95 is part of the interface between the plug assembly 90 and the receptacle assembly 10. The depicted body 92 includes a surface 94 that includes cooling grooves 96 that extend substantially the length of the body that is intended to be inserted into the port 12 and in an embodiment extend along the top surface to an end 92 a that is past the front 60 a of the projection 60. The cooling grooves 96 allow air to flow through the port 12 when the plug assembly 90 is inserted into the port 12 and substantially improves cooling efficiency compared to prior art designs as the air flow is able to directly cool the plug assembly 90.

The receptacle assembly 10 includes a top wall 31 a, two side walls 31 b and a rear wall 31 c. A bottom wall 31 d can also be provided to improve shielding performance. A housing 50 is positioned in the cage and supports a wafer array 40. The housing 50 includes a projection 60 and a card slot 62 is provided in the projection 60. The card slot 62 includes a biasing element 68 that is configured to engage the paddle card 95 and bias the paddle card 95 to one side of the card slot 62. This allows for control of the paddle card 95 vis-a-vis the card slot and removes a range of tolerances that would otherwise be associated with the location of the pads on the paddle card 95 versus the location of contacts provided in the card slot 62. The housing 50, which can be formed of an insulative resin, further includes air channels 52 that allow for additional cooling and can have a back support 54 that snaps onto the housing 50 and helps secure the wafer array 40 in position.

As is known, the wafer array 40 includes a plurality of wafers 41 and each wafer 41 supports a plurality of terminals that each can have a tail 42 and a contact 44. The contacts 44 are positioned on in the card slot 62 and typically will be arranged so that some contacts are positioned on opposing sides of the card slot 62. To improve performance, short ribs 67 separate the signal terminals that form a differential pair 45 while long ribs are positioned between the signal terminal and the corresponding ground terminals. As the contacts 44 are positioned in a single row on a constant pitch, the short ribs 67 provide electrical isolation and protection between signal terminals while the long ribs 65 increase the dielectric contact between the signal terminals and the ground terminal compared to the dielectric constant associated with the signal terminals so as to provide preferential coupling between the differential pair (e.g., even though the terminals are on a constant pitch, more energy is carried in the differential coupling than symmetry would suggest). In other words, the ribs 65, 67 form grooves that help protect the contacts 44 and the signal terminals are aligned with a notch 69 formed in the card slot 62 that helps lower the dielectric constant near the signal terminal contacts.

The cage includes a front portion 32 that can provide structure support for the rest of the cage 30 and the front portion 32, which can include shoulders 38 that extend from the bottom wall 31 d, can support an EMI gasket 32 a that can be positioned in the ports and that helps minimize EMI radiation. Light pipes 29 can be provided (they are shown as being transparent like in the Figs. as they often are transparent) and typically would be configured to direct light from the supporting circuit board toward a front face 11 a, usually between the two ports.

To help define the ports 12, a central support 21 is provided. The central support 21 can be formed of a top wall 21 a and a bottom wall 21 b that are supported by the sides 31 b and help define a bottom or top of a port, respectively. A central duct 26 is defined by the central support 21. The top and bottom walls 21 a, 21 b can include notches 23 to further allow airflow into the ports 12. An insert 15 can be positioned in the central support 21. The insert 15 includes a front wall 16 with front apertures 16 a that allow air to flow through the front wall 16 and further allows for indicators that use light pipes to illuminate the corresponding area.

The connector assembly also includes a middle wall 70 that has middle array 72 with middle apertures 72 a and further includes apertures 72 b positioned in the top port 12 and includes apertures 72 c positioned in the bottom port 12. The apertures 72 a, 72 b, 72 c allow air to flow past the middle wall 70 while still providing desireable EMI protection. The middle wall 70 has cutouts 73 that allow the light pipes 29 to extend past the middle wall 70. Thus the depicted design allows for the use of light pipes while still providing improved cooling capabilities.

Rear apertures 34 a allow air to flow past the rear wall 31 c. The housing 50 is designed so that there is sufficient room on the side of the housing 50 so that air can flow past from the middle wall 70 to the rear wall 31 c. As can be appreciated, therefore, the connector assembly 10 is configured to allow for substantial air flow to pass from the front face 11 a to a rear face 11 b (or in the opposite direction). Specifically, if air is flowing from the front face 11 a to the rear face 11 b then an insert 15 is configured to allow air to flow through the front wall 16, air flows through the central duct 26, then through a middle wall 70, past the housing 50 and finally out rear wall 31 c.

As can be appreciated, a card slot is disclosed in the embodiments depicted that provides terminals at a 0.60 or 0.65 mm pitch. To provide for the necessary tolerances, the biasing element 68 is provided in the card slot and the biasing element 68 helps ensure the location of one side of the paddle card is known (one side is biased against one side of the card slot). This reduces the tolerance stack-up such that a 0.6 mm pitch connector is possible with a conventional paddle card based mating connector. Compared to prior art designs this provides a further improvement over biasing the entire plug connector as it has been determined that there is the potential for tolerance stack-up of the location of the paddle card 95 within the plug connector 90. The depicted embodiment, however, eliminates that form of tolerance stack-up as an edge 95 a of the paddle card 95 becomes a datum. The tolerances can be further improved if the edge 95 a of the paddle card 95 is used to align pads 97 that are positioned on the paddle card 95. Otherwise, the standard construction techniques used to form paddle cards would result in a tolerance stack-up that would prevent 0.6 mm pitch terminal from working in a reliable fashion.

It should be noted that if the terminals are on a larger pitch (such as 0.7 or more) then the biasing element can be omitted. The connector design still provides desirable cooling properties for what is otherwise a compact package and the cooling features can be incorporated into connectors regardless of the pitch of the terminals.

The cable assembly need not provide the cooling grooves in all situations. If, for example, the cable assembly is a passive device then there will be little need for cooling and the cooling grooves can be omitted.

The disclosure provided herein describes features in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. 

We claim:
 1. A plug connector, comprising: a housing having a top surface and a bottom surface and a front end, the housing being formed of a thermally conductive material; and a paddle card positioned in the housing, the paddle card extending toward a front end of the plug connector, wherein one of the top surface and the bottom surface has cooling grooves extending along a length of the plug connector, the cooling grooves configured, in operation, to allow air to flow along the top surface of the housing toward the front end when the housing is inserted into a receptacle port.
 2. The plug connector of claim 1, wherein the paddle card has contact pads on a 0.6 mm pitch and the contact pads are aligned with a side of the paddle card.
 3. The plug connector of claim 1, wherein the cooling grooves extend along the entire portion of the housing.
 4. A connector system, comprising: a receptacle including a cage that defines a port and a housing positioned in the cage, the cage having a front face and a rear wall, the housing providing a card slot aligned with the port, the card slot including a plurality of grooves, wherein the housing supports a first plurality of terminals that have contacts positioned in the grooves; and a first plug connector positioned in the port and having a paddle card with pads that engages the contacts, the first plug connector including a body with a plurality of cooling grooves that extend along a length of the body, the cooling grooves configured to allow air to flow through the connector from the front face toward the rear wall so as to help directly cool the first plug connector.
 5. The connector system of claim 4, wherein the terminals are on a 0.6 mm pitch.
 6. The connector system of claim 4, wherein the port is a first port and the receptacle includes a second port positioned above the first port, wherein the card slot is a first card slot, the housing further providing a second plurality of terminals with contacts positioned in a second card slot aligned with the second port, the second card slot having grooves that help protect the contacts positioned therein and a second plug connector with a body positioned in the second port, the second plug connector having a paddle card that engages the contacts positioned in the second card slot, wherein the body of the second plug connector includes cooling groves that extend along a length of the body of the second plug connector. 